The Structures of the Bulky Basic Phosphine Sulfides Tris(2,6-Dimethoxyphenyl)Phosphine Sulfide (DMPP[dbnd]S) and Tris(2,4,6-Trimethoxyphenyl)Phosphine Sulfide (TMPP[dbnd]S)
“…Hence, the electron-donating tertbutyl, 4-OSi(CH 3 ) 3 and 4-OH substituents may contribute to a slight elongation of P=S and P=Se distances. Among all the surveyed structures for P=S, only one has a 4-OR substituent (CSD refcode: ZEJLUV), 58 while for P=Se, three structures have this pattern (refcodes: ITEMOL, 59 QAJZEI, 39 and VIFJID). 60 The two crystal forms of diphenyl-(4-hydroxy-3,5-ditertbutylphenyl)-phosphine oxide that we obtained, structures 2c and 2c′ (Figures 7a/S7 and 7b/S8, respectively), differ in that a disordered toluene solvent molecule is found in the 2c′ crystal lattice, which was removed from the refinement model using a solvent mask.…”
Section: ■ Introductionmentioning
confidence: 99%
“…These layers are perforated by the perpendicular, solvent-occupied channels whose volume occupancy presumably enables this interesting architecture. Much larger level 2 rings surround the solvent channels, described simultaneously by R 8 4 (56), R 8 5 (58), R 8 6 (60), and R 8 7 (62) graph sets. Apparently, the strong H-bonding that occurs only with itself in the 4c′ structure is robust enough to reject further interaction with n-butanol or water.…”
Synthesis and molecular and supramolecular structures of a series of triarylphosphines P(Ph) 3−n {4-RO-3,5-( t Bu) 2 -C 6 H 2 } n (n = 1, 3; R = SiMe 3 , H) are reported. Chemical oxidation products E=P(Ph) 3−n {4-RO-3,5-( t Bu) 2 -C 6 H 2 } n (E = O, S, and Se; n = 1, 3; R = SiMe 3 , H) are also reported. Crystal structures of the reported compounds were determined by single-crystal X-ray diffraction, using a Hirshfeld atom refinement with NoSpherA2 through OLEX2, which provides an average improvement in C−C bond distance precision of 35%. Phosphine basicity for the phosphines with n = 1, R = H and n = 3, R = SiMe 3 , H was determined using the 1 J P,Se values of the respective selenides; 1 J P,Se = 699 Hz for E = Se, n = 3, and X = H identifies the most basic triarylphosphine ever reported. Intermolecular interactions allow classification of the 17 structures into 4 categories: those with only dispersion-induced short contacts, those with frustration of H-bonding, those with only classic H-bonding, and those with combinations of classic and frustration of H-bonding. A "double phenol embrace" classified by an R 2 2 (4) graph set is a weak intermolecular synthon organizing lattices with 2,6-ditertbutylphenol functional groups. Classic H-bonding occurs only when E = O.
“…Hence, the electron-donating tertbutyl, 4-OSi(CH 3 ) 3 and 4-OH substituents may contribute to a slight elongation of P=S and P=Se distances. Among all the surveyed structures for P=S, only one has a 4-OR substituent (CSD refcode: ZEJLUV), 58 while for P=Se, three structures have this pattern (refcodes: ITEMOL, 59 QAJZEI, 39 and VIFJID). 60 The two crystal forms of diphenyl-(4-hydroxy-3,5-ditertbutylphenyl)-phosphine oxide that we obtained, structures 2c and 2c′ (Figures 7a/S7 and 7b/S8, respectively), differ in that a disordered toluene solvent molecule is found in the 2c′ crystal lattice, which was removed from the refinement model using a solvent mask.…”
Section: ■ Introductionmentioning
confidence: 99%
“…These layers are perforated by the perpendicular, solvent-occupied channels whose volume occupancy presumably enables this interesting architecture. Much larger level 2 rings surround the solvent channels, described simultaneously by R 8 4 (56), R 8 5 (58), R 8 6 (60), and R 8 7 (62) graph sets. Apparently, the strong H-bonding that occurs only with itself in the 4c′ structure is robust enough to reject further interaction with n-butanol or water.…”
Synthesis and molecular and supramolecular structures of a series of triarylphosphines P(Ph) 3−n {4-RO-3,5-( t Bu) 2 -C 6 H 2 } n (n = 1, 3; R = SiMe 3 , H) are reported. Chemical oxidation products E=P(Ph) 3−n {4-RO-3,5-( t Bu) 2 -C 6 H 2 } n (E = O, S, and Se; n = 1, 3; R = SiMe 3 , H) are also reported. Crystal structures of the reported compounds were determined by single-crystal X-ray diffraction, using a Hirshfeld atom refinement with NoSpherA2 through OLEX2, which provides an average improvement in C−C bond distance precision of 35%. Phosphine basicity for the phosphines with n = 1, R = H and n = 3, R = SiMe 3 , H was determined using the 1 J P,Se values of the respective selenides; 1 J P,Se = 699 Hz for E = Se, n = 3, and X = H identifies the most basic triarylphosphine ever reported. Intermolecular interactions allow classification of the 17 structures into 4 categories: those with only dispersion-induced short contacts, those with frustration of H-bonding, those with only classic H-bonding, and those with combinations of classic and frustration of H-bonding. A "double phenol embrace" classified by an R 2 2 (4) graph set is a weak intermolecular synthon organizing lattices with 2,6-ditertbutylphenol functional groups. Classic H-bonding occurs only when E = O.
“…This was the first example of a six-membered ring formationvia carbonyl oxygen coordination. Earlier work − was concentrated on the formation of phosphorus compounds containing four- and five-membered cyclic systems showing oxygen coordination. …”
A series of phosphorus compounds 1-5 containing carbonyl or carboxyl groups was obtained and subjected to X-ray analysis. Syntheses of the phosphoranes 1 and 5 were effected by oxidation reactions using potassium permaganate, while the phosphine oxide 2 was obtained by oxidation with hydrogen peroxide. The readily available phosphines 3 and 4 were included in the study. The structures revealed that P-O coordination occurred for 1-3 in the presence of extensive hydrogen bonding and led to trigonal bipyramidal geometries. A similar structure was observed for 4 in the absence of hydrogen bonding. (31)P chemical shifts indicate retention of the basic coordination geometries in solution. Consideration of the chirality of the phosphoranes 1 and 5 leads to a pair of mirror images that are possible in solution but exist in preferred isomeric forms in the crystalline state. Evaluation of the energies of two competing bonding types indicated a range for P-O coordination above and below the hydrogen bond energy. The results suggest that phosphoryl transfer enzyme mechanisms should benefit by taking into account donor interactions to phosphorus by residues at active sites in addition to the inclusion of hydrogen bonding interactions.
“…Recent literature on carbonyl donor action has demonstrated the formation of four- 19-21 and five-membered 22-24 ring systems. With the inclusion of OR groups, a wider variety of donor−acceptor interactions is known giving similar size rings. ,− Some examples are shown in Chart , which includes three examples − with potential for donor−acceptor interactions but whose X-ray structures give excessively long P−O distances. Of the ones that form small-membered ring systems, they are by necessity rigid compared to that for the conformationally more flexible six-membered cyclic systems employed in the present study.…”
The new cyclic compound 2,2'-sulfurylbis(4-methyl-6-tert-butylphenyl) methyl 2-benzoate phosphite, O(2)S[(t-Bu)MeC(6)H(4)O](2)(OC(6)H(4)CO(2)Me)P (3), containing a salicylate ligand was synthesized from 2,2'-sulfurylbis(4-methyl-6-tert-butylphenyl) chlorophosphite and methyl salicylate in the presence of triethylamine in ether solution. X-ray analyses of bis(methyl salicylate-O)phenylphosphine, (OC(6)H(4)CO(2)Me)(2)PPh (1), and bis(methylsalicylato-O)phenyl(tetrachlorophenylene-1,2-dioxy)phosphorane, (O(2)C(6)Cl(4))(OC(6)H(4)CO(2)Me)(2)PPh (2), as well as that for 3 were obtained. The phosphane 1 has a pseudo trigonal bipyramidal (TBP) structure due to coordination of a carbonyl oxygen atom at an axial site. The cyclic phosphorane 2 and the phosphite 3 lack any coordination from salicylate ligands. This results in a TBP geometry and a pyramidal geometry respectively for 2 and 3. Comparisons with X-ray structures for carboxylate-containing phosphorus compounds exhibiting oxygen coordination show the formation of four- and five-membered cyclic systems. Thus, 1 appears to be the first example of formation of a six-membered ring via carbonyl oxygen coordination. Reference is made to the tyrosyl-tRNA synthetase system where it is proposed that carbonyl oxygen atom coordination is a likely occurrence in the transition state on the basis of the analysis presented in this work.
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